Question about: "Use SMTP to send system mails"

I am using that option to send out system email through Gmail's SMTP server BUT I still get emails that are not sent out through that server but through my own so I was wondering what is considered a "system mail" by ISPCFG3?

i.e. the latest example of an email which did NOT go out through this external server had this subject: "The mailbox [email protected] is near or over quota." - is this not a system email?

The reason why I noticed something was wrong is because I use SPF and DKIM for this domain (where my Emails are hosted via Google Apps) so in my Gmail inbox I see this undelivered email. I left my email address visible, just blanked the client's address. Btw. this was the over-quota mail to myself, the same happens with the email sent to the client himself.

I got the same email today, still saying unauthenticated email is not accepted. Any more tips or things to check? I don't understand why it says unauthenticated. I provided a user name and an app password.

Based on my own experience there is a different between using relay and smtp. Using the later, via your old gsuite free account, you can only securely use [email protected] and not [email protected]. The proper party or forum to ask and confirm about this is Google itself.

Based on my own experience there is a different between using relay and smtp. Using the later, via your old gsuite free account, you can only securely use [email protected] and not [email protected]. The proper party or forum to ask and confirm about this is Google itself.

Click to expand...

I think you introduced the idea of relaying into this discussion. All I am trying to do is using the Gmail SMTP Server for system emails. The system admin's email is set to my Gmail address. The point is, somehow the error is talking about unauthenticated emails when I have setup my Gmail credentials to be used so how can that be?

I was referring your above logs where it says you are using smtp as a relay, so I mentioned it a bit, but my point is still about smtp and the right sending email address and domain as also stated by @till above.

host gmail-smtp-in.l.google.com[108.177.15.26] said: 550-5.7.1 Unauthenticated email from pacura.ru is not accepted due to domain's 550-5.7.1 DMARC policy. Please contact the administrator of pacura.ru domain if 550-5.7.1 this was a legitimate mail. Please visit 550-5.7.1 https://support.google.com/mail/answer/2451690 to learn about the 550 5.7.1 DMARC initiative. t63si6412399wma.109 - gsmtp (in reply to end of DATA command)

Click to expand...

About the logs it also mentioned about dmarc, did you read the given link and try its given solutions, if any?

is that my local postfix/smtp server handed over the email to this server: gmail-smtp-in.l.google.com and then that server responded with dsn=5.7.1, status=bounced

the relaying server (in this case Google#s SMTP) obviously does not accept unauthenticated emails, but why is ISPCFG not using the authentication info I provided? So what I am saying is that as soon as my server provides authentication to Google's SMTp its not longer relaying but delivering?